1. Field of the Invention
The present invention relates generally to pressure differential-driven engines. More specifically, the invention relates to an engine using a pressurized working fluid to produce cyclic motion.
2. Related Art
Engines for converting energy from one form to another have been used for many years in a number of applications. Perhaps the best known example, the internal combustion (“IC”) engine, converts energy stored in the form of petroleum-based fuel into mechanical energy. IC engines have been successfully utilized to power vehicles, electric generators, lawn mowers, etc. Typical IC engines convert energy stored in fuel into mechanical energy by burning or detonating the fuel and extracting force generated in a cylinder/piston assembly. Typical IC engines use the force generated in the cylinder/piston assembly to drive some type of output device, such as a rotary crankshaft, a direct rotary output, or other power take-off device.
While IC engines have been used with success in a variety of applications, they can be problematic for a number of reasons. One such problem relates to the efficiency of the energy conversion process. For instance, typical IC engines have efficiency ratings in the range of 30–50%, with 50% considered to be highly efficient and generally only achievable by large, highly precise, and, therefore, costly engines. In addition, the process of converting fossil fuels into useful mechanical energy often results in large degrees of pollution released into the atmosphere, which can be detrimental to the environment in general, and particularly to humans who are exposed to or breathe the polluted air. As more and more IC-powered vehicles are produced and operated by an increasingly greater population, the levels of pollution produced by IC-powered vehicles is becoming an increasingly greater concern. In addition, IC engines necessarily create a great deal of heat, as they produce a series of combustion events which generate force and associated byproduct of heat. This can be problematic for applications which benefit from low-heat production engines.
In addition to IC engines, a variety of energy transducers have been developed for converting energy from one form to another. Examples of such transducers include heat engines, fluid compressors, hydraulic actuators, etc.